The estimated resident population of the Northern Territory at 30 June 2008 was 219,800, an increase of 19,800 people or 9.9% (an average of 1.9% per year) since 30 June 2003.

Just over half (54.9%) of the Northern Territory's population resided in the Darwin Statistical Division (SD), which consists of Darwin City, Palmerston-East Arm and Litchfield Shire Statistical Subdivisions (SSDs), with the remaining 45.1% spread across the vast Northern Territory - Bal SD, which stretches from the junction of the Northern Territory, Western Australia and South Australia borders (Surveyor Generals Corner) in the south-west to Cape Wessel off the coast of Arnhem Land in the north-east.

For Local Government Areas (LGAs) or Statistical Local Areas (SLAs), unless otherwise stated, this summary excludes those with a population of less than 1,000 as at 30 June 2008.

The age structure of people living in Darwin SD was generally older than for those residing in Northern Territory - Bal SD. In 2008, Darwin SD had higher proportions of people in the five year age groups from 30-34 years onwards, while Northern Territory - Bal SD had higher proportions in the younger age groups, particularly from 0-4 years to 20-24 years.

Within Darwin SD, the highest proportions of both males and females were in the 25-29 years age group (4.5% and 4.3 % respectively). In contrast, the highest proportion of males in Northern Territory - Bal SD was in the 5-9 years age group (4.8%), while the highest proportions of females were in the 5-9 and 25-29 years age groups (both 4.5%).

At 30 June 2008, the median age (the age at which half the population is older and half is younger) for the Northern Territory was 31.1 years. The Northern Territory continues to have the lowest median age of Australia's states and territories, with the next lowest being the Australian Capital Territory (34.7 years), and continues to be unique among the states and territories in having a male median age (31.4 years) which was higher than the female median age (30.8 years).

The SSD of Finniss had the highest median age of all the SSDs in the Northern Territory at 43.4 years, which placed it just outside the highest twenty median ages of all the SSDs in Australia. Next highest in the Northern Territory were Litchfield Shire (36.6 years) and Darwin City (33.9 years). Six of the other seven SSDs in the Northern Territory had the lowest median ages in Australia, led by Alligator (26.4 years), Lower Top End NT (26.7 years) and Bathurst-Melville (27.2 years).

Coomalie (S) had the highest median age of all the LGAs in the Northern Territory at 43.1 years followed by Litchfield (S) (36.6 years) and Darwin (C) (33.9 years). The LGAs of Victoria-Daly (S) (23.6 years) and Roper Gulf (24.3 years) had the lowest median ages in the Northern Territory.

At 30 June 2008, there were 52,300 children in the Northern Territory, with boys outnumbering girls by 1,600. This age group comprised 23.8% of the population, which was the highest proportion in any Australian state or territory.

The SSD with the largest proportion of children was Alligator (30.0%) followed by Lower Top End NT (29.9%). Alligator has had the highest proportion of children each year since June 2003.

The three LGAs with the largest proportions of children were Victoria-Daly (S) (33.7%), Roper Gulf (S) (31.5%) and East Arnhem (S) (30.7%). The SLA with the highest proportion of children in Darwin (C) was City - Remainder (29.9%), which includes both RAAF Base Darwin and Defence Establishment Berrimah married quarters. The SLA in Palmerston (C) with the highest proportion of children was Moulden (31.9%), while Alice Springs (T) LGA's highest was in Alice Springs (T) - Larapinta (25.2%).

The SLA of Victoria-Daly (S) - Wadeye and OS had the highest proportion of children aged 0-14 years in the Northern Territory (37.9%), as it had for the previous five years. The next highest proportion was in West Arnhem (S) Bal (32.2%). Both SLAs have large Indigenous populations and higher fertility rates than the Northern Territory population as a whole.

POPULATION AGED LESS THAN 15 YEARS, Statistical Local Areas, Northern Territory - 30 June 2008

At 30 June 2008, the number of people aged 15-64 years was 156,300, or 71.1% of the Northern Territory's population. Darwin City (74.0%) and Litchfield Shire (73.0%) SSDs had the highest proportions of people aged 15-64 years.

The SLA of Litchfield (S) - Pt A (on the outskirts of Darwin and Palmerston), continued to have the highest proportion of its population of working age (89.3%), mainly due to the presence of a large military base. There were also high proportions in Yulara (86.3%), Stuart Park (85.1%), City - Inner (84.9%) and Larrakeyah (81.3%).

The LGAs with the highest proportions of their populations in this age group were Darwin (C) (74.0%), Litchfield (S) (73.0%) and Alice Springs (T) ( 72.7%). Unincorporated NT (which consists of the SLAs of Alyangula, East Arm, Finniss-Mary, Nhulunbuy and Yulara) also had a high proportion (77.0%) of people of working age.

WORKING AGE POPULATION (AGED 15-64 YEARS), Statistical Local Areas, Northern Territory - 30 June 2008

At 30 June 2008, the proportion of people aged 65 years and over in the Northern Territory was the lowest among the Australian states and territories at 5.1%. Nationally the proportion was 13.2%. The total number of people in this age group in the Northern Territory, rose from 8,000 (4.0% of the Northern Territory population) in June 2003 to 11,200 in June 2008.

The SSDs of Finniss and Darwin City had the highest proportions of residents aged 65 years and over (10.2% and 6.6% respectively). All Northern Territory SSDs experienced an increase in the number of people aged 65 years and over in the five years from June 2003 to June 2008.

At 30 June 2008, the Northern Territory's sex ratio (the number of males per 100 females) was 107.7, with 114,000 males and 105,800 females. The Northern Territory continued to have the highest sex ratio of all the states and territories, followed by Western Australia with 102.6.

Central NT SSD was the only SSD to have fewer males than females with a sex ratio of 98.8. The SSDs with the highest sex ratios were Litchfield Shire (127.2) and Finniss (118.9).

At the SLA level, Litchfield (S) - Pt A, which contains a large military base, had the highest sex ratio (299.5), followed by West Arnhem (S) - Jabiru (148.0), which in the five years since June 2003 has replaced City - Inner as having the second highest sex ratio in the Northern Territory. The lowest sex ratios occurred in Victoria-Daly (S) - Wadeye and OS (90.0) and Alice Springs (T) - Charles (90.6).